1. Field of the Invention
The present invention relates to improvements in a corrugating roll unit exchanging apparatus for a single facer in a corrugating machine.
2. Description of the Prior Art
Before describing a corrugating roll unit exchanging apparatus in the prior art to be associated with a single facer in a corrugating machine, a first description will be made concerning the construction and function of a single facer. FIG. 3 is a cross-sectional view of a general single facer. In this figure, reference character G designates a floor surface, reference numeral 11 designates an upper corrugating roll having a corrugated surface, numeral 13 designates a lower corrugating surface for shaping a core paper sheet into a corrugated form by meshing with the upper corrugating roll 11, numeral 12 designates the core paper sheet fed between the above-mentioned respective corrugating rolls to be shaped into a corrugated form, numeral 18 designates a preheat roll for preheating the core paper sheet before shaping, numeral 17 designates a pasting device for applying paste to the corrugation crest portions of the shaped core paper sheet 12, numeral 16 designates paste stored in the same device, numeral 14 designates a liner, numeral 15 designates a pressing roll for making the core paper sheet 12 pasted at the corrugation crest portions and the above-mentioned liner 14 stick together by causing them to pass between the lower corrugating roll 13 and itself under pressure, and numeral 1 designates a single-faced corrugated fibreboard produced through the operations of the above-described respective portions. It is to be noted that in the case where the core paper sheet 12 and the liner 14 are made to stick together by means of the paste 16 transferred to the corrugation crest portions, an appropriate pressing force under a given condition and heating of the paste 16 are necessary, and so, between the respective rolls are provided contact pressure adjusting devices and within the rolls 11, 13 and 15 are assembled devices for introducing steam or high-temperature oil into the rolls to be able to preset the rolls at a high temperature. In addition, the core paper sheet 12 is wound around the preheat roll 18 in the just preceding step of the process to be subjected to quality control and preliminary warm-up.
Next, description will be made of a portion R called "corrugating roll unit" which principally consists of an upper corrugating roll and a lower corrugating roll. Reference numeral 19 designates a pair of side frames for rotatably holding the shaft of the lower corrugating roll via bearings on the opposite sides thereof, numeral 21 designates a pair of arms for rotatably holding the shaft of the upper corrugating roll on the opposite sides thereof, numeral 20 designates a fulcrum shaft for rotatably connecting the same arms 21 to the side frames 19, numeral 22 designates a cylinder provided between the side frame 10 and the arm 21 for rotating the arm 21 with respect to the side frame 19 by changing its operating pressure and thereby adjusting the contact condition between the upper and lower corrugating rolls, and reference numerals 23 and 24 designate stays for connecting the pair of side frames to each other. The corrugating roll unit R assembled by engaging the upper and lower corrugating rolls via both side frames with the aforementioned structure, is fastened to a main body of a single facer by means of three bolts 9 on each side, and it can be arbitrarily attached or detached according to necessity.
By means of the single facer having the above-described structure, the core paper sheet 12 is shaped, has its corrugation crest portions pasted and is made to stick to the liner 14, and they are delivered as a single-faced corrugated fibreboard sheet 1. Depending upon a specification such as a thickness, a width and the like of the core paper sheet, the contact condition between the upper and lower corrugating rolls is adjusted by the cylinder 22. In the single-faced corrugated fibreboard sheet 1 are formed various types of flutes depending upon the corrugated wave shape, and an appropriate type is selected according to the desired use. However, since the flutes which can be formed by means of a set of corrugating rolls 11 and 13 are of only one type, upon change of the flutes as a result of order change, it is necessary to replace and exchange both the upper and lower corrugating rolls. Accordingly, in such case the corrugating roll unit R itself if exchanged.
FIG. 4 is a front view of a corrugating roll unit exchanging apparatus in the prior art, and FIG. 5 is a side view of the same apparatus. In this figure, reference character G designates a floor surface, character F designates a single facer, character R designates a corrugating roll unit forming a part of the single facer, reference numeral 19 designates side frames of the corrugating roll unit, numeral 26 designates a pair of parallel permanent rails provided above the single facer, numeral 25 designates suspending devices movably held by the respective rails and capable of suspending the corrugating roll unit via its side frames 19, numeral 27 designates a pair of parallel additional rails to be added upon exchange of the corrugating roll unit, numeral 27a designates connecting metals for connecting one ends of the respective additional rails to the respective ends of the permanent rails, numeral 28 designates gate-shaped posts for supporting the other ends of the above-mentioned additional rails 27, numeral 10 designates a transport truck for transporting a corrugating roll unit, numeral 10a designates guide rails for the same truck, arrows indicating a carry-out direction of the corrugating roll unit, and reference character S indicates a moving distance of the suspending devices. In addition, reference character R' and reference numeral 10' in FIG. 5 indicates the positions after movement of the items denoted by character R and numeral 10, respectively.
In the above-described apparatus, exchange of a corrugating roll unit as a result of order change is carried out in the following manner. At first, the three fastening bolts 9 on each side (FIG. 3), which fixedly secure the corrugating roll unit R to the single facer F, are extracted and also connection of steam pipings and the like not shown is released, then the corrugating roll unit R is once hung up by means of the suspending devices (hoists) 25, subsequently it is carried out in the axial direction of the rolls to the outside, and it is placed on the transport truck 10 held in a standby state and is transported to a predetermined housing position. Subsequently, a corrugating roll unit R for the next order is carried in via the transport truck 10 up to a predetermined position on the side of the single facer. Thereafter, operations inverse to the aforementioned operations are effected to assemble the new corrugating roll unit R at a predetermined position of the single facer, and the released steam pipings and the like are reconnected.
The above-described suspending devices 25 are adapted to roll along two rails 26 installed above the single facer, extension in the lengthwise direction of these rails necessitated for carrying out the corrugating roll unit to the outside, is effected by mounting additional rails 27 detachably provided in continuation to the permanent rails 26 fixedly secured to ceiling beams above the single facer, and the free end portions of the additional rails 27 are supported by posts 28 erected on the floor. These additionally provided additional rails 27 and posts 28 are removed after replacing exchange of the corrugating roll unit R.
As described above, in the corrugating roll unit exchanging apparatus in the prior art, each time when a corrugating roll unit is to be exchanged it was necessary to connect additional rails to permanent rails fixedly secured to a ceiling and to provide posts for supporting the free ends of the additional rails, and so, upon exchange of a corrugating roll unit, complicated mount and dismount works of additional rails and the like were necessitate before and after the exchange. Consequently, there was time loss caused by the exchange work, and since the work was accompanied by danger, frequent change of flutes was so difficult that a production scheme of corrugated fibreboard sheets was largely influenced thereby.